# 9.3. Mouse

This module allows you to configure your pointing device. Your pointing device may be a mouse, a trackball, a touchpad, or another piece of hardware that performs a similar function.

## 9.3.1. Use

Pointer Acceleration. This option allows you to change the relationship between the distance that the mouse pointer moves on the screen and the relative movement of the physical device itself (which may be a mouse, trackball, or some other pointing device.)

A high value for the acceleration multiplier will lead to large movements of the mouse pointer on the screen, even when you only make a small movement with the physical device.

| A multiplier between '1x' and '3x' will works well for many systems. With a multiplier over '3x' the mouse pointer may become difficult to control.

Drag Threshold. The threshold is the smallest distance that the mouse pointer must move on the screen before acceleration has any effect. If the movement is within the threshold, the mouse pointer moves as if the acceleration were set to '1x'.

Thus, when you make small movements with the physical device (e.g. mouse), you still have fine control of the mouse pointer on the screen, whereas larger movements of the physical device will move the mouse pointer rapidly to different areas on the screen.

You can set the threshold value by dragging the slider button or by clicking the up/down arrows on the spin-button to the left of the slider.

| In general, the higher you set the Pointer Acceleration value, the higher you'll want to set the Drag Threshold value. For example, A Drag Threshold of '4pixels' may be appropriate for a Pointer Acceleration of '2x', but '10pixels' might be better for '3x'.

Button Mapping. If you are left-handed, you may prefer to swap the functions of the left and right buttons on your pointing device by choosing the 'left-handed' option. If your pointing device has more than two buttons, only those that function as the left and right buttons are affected. For example, if you have a three-button mouse, the middle button is unaffected.

Single Click Activates/Opens. Checking this option allows you to activate/open icons with a single click of the left button on your pointing device (e.g. mouse). This behavior is consistent with what you would expect when you click links in most web browsers. If you would prefer that single clicking merely selects an icon or file, and that double clicking is required to open it, then uncheck this option.

Automatically Select Icons. If you check this option, pausing the mouse pointer over an icon on the screen will automatically select that icon. This may be useful when single clicks opens icons, and you only want to select the icon without opening it.

| You can still select an icon or file without opening it, even when Single Click Opens is checked. This is done by either holding down the Ctrl-key and then clicking, or by dragging a box around the icon(s) or file(s) which you wish to select.

If you have activated this option, you can use the slider to select how long the mouse pointer must rest on an icon before it becomes selected.

Pointer Shape Changes. When this option is checked, the shape of the mouse pointer changes whenever it is over an icon.

| This option should be checked in most situations. It gives more visual feedback and says, in essence, if you click here, something will happen.

## 9.3.2. Author

This section of the KDE Control Center manual written by: Ellis Whitehead `<ewhitehe@uni-freiburg.de>`